The document details the sewage treatment process, including the removal of contaminants from wastewater to produce effluent and solid waste (sludge). It outlines the various treatment stages: primary (solid separation), secondary (biological treatment), and tertiary (disinfection), while also highlighting different methods and technologies involved in each stage. Additionally, it addresses the treatment of sludge, including aerobic and anaerobic digestion, and the potential for repurposing treated water for irrigation or groundwater recharge.

2. ANUDEEP NEMA
Ph.D , SVNIT Surat

3.  Usually refer to sewage treatment, or domestic
wastewater treatment
 process of removing contaminants from
wastewater, both runoff and domestic

4.  To produce waste stream (effluent)
 To produce solid waste (sludge)
 To discharge or reuse them back into the
environment

5.  Residences (kitchen, bathroom)
 Commercial institution
 Industrial institution (usually require
specialized treatment process)

6.  collected and transported via a network of
pipes and pump stations to a municipal
treatment plant

7.  Primary
 solids are separated
 Secondary
 dissolved biological matter is converted into a solid mass by
using water-borne bacteria
 95% of the suspended molecules should be removed
 Tertiary
 biological solids are neutralized then disposed, and treated
water may be disinfected chemically or physically

8.  Mechanical treatment
 Influx (Influent)
 Removal of large objects
 Removal of sand and grit
 Primary Sedimentation
 Biological treatment
 Trickling bed filter
 Activated sludge
 Chemical treatment
 Disinfection

9.  Remove large objects
 Ex: sticks, rags, toilet paper, tampons
 Raked screen
 Clog equipment in sewage treatment plant

10.  typical materials that are removed during
primary treatment include
 fats, oils, and greases (aka FOG)
 sand, gravels and rocks (aka grit)
 larger settleable solids including human waste, and
 floating materials

11.  Sand catcher
 Remove sand and grit
 Control wastewater velocity
 Sand grit and stone settle
 Keep suspended organic matter in water
 Damage equipments in the remaining treatment
stage
 Landfill

12.  Primary Sedimentation
Tank
 Remove grease, oil
 Fecal solid settle,
floating material rise to
the surface
 Produce a homologous
liquid for later biological
treatment
 Fecal sludge are
pumped to sludge
treatment plant

13.  Degrade biological content (dissolved organic
matter) of the sewage
 Ex: human waste, food waste, soaps, detergent
 Added bacteria and protozoa into sewage
 3 different approaches
 Fixed film system
 Suspended film system
 Lagoon system

14.  Fixed Film Systems
 grow microorganisms on substrates such as rocks,
sand or plastic
 wastewater is spread over the substrate
 Ex: Trickling filters, rotating biological contactors

15.  Spread wastewater
over microorganism
 made of coke
(carbonised coal),
limestone chips or
specially fabricated
plastic media
 Optimize their
thickness by insect or
worm grazing

16.  Suspended Film Systems
 stir and suspend microorganisms in wastewater
 settled out as a sludge
 pumped back into the incoming wastewater
 Ex: Activated sludge, extended aeration

17.  mixed community of microorganisms
 Both aerobic and anaerobic bacteria may exist
 Biological floc is formed

18.  aeration tank
 oxygen is introduced into the system

19.  aeration source
 ensure that adequate oxygen is fed into the tank
 provided pure oxygen or compressed air

20.  secondary clarifiers
 activated-sludge solids separate from the
surrounding wastewater

21.  Activated sludge
outflow line
 Pump activated sludge
back to the aeration
tank
 Effluent outflow line
 discharged effluent into
bay or tertiary
treatment plant

23.  Lagoon Systems
 hold the waste-water for several months
 natural degradation of sewage
 Usually reeds are preferred

24.  remove disease-causing organisms from
wastewater
 3 different disinfection process
 Chlorination
 UV light radiation
 Ozonation

25.  Most common
 Advantages: low
cost & effective
 Disadvantages:
chlorine residue
could be harmful to
environment

26.  Damage the genetic
structure of bacteria,
viruses and other
pathogens.
 Advantages: no
chemicals are used
 water taste more natural
 Disadvantages: high
maintenance of the UV-
lamp

27.  Oxidized most pathogenic microorganisms
 Advantages: safer than chlorination
fewer disinfection by-product
 Disadvantage: high cost

28.  discharged into a stream, river, bay, lagoon or
wetland
 used for the irrigation of a golf course, green
way or park
 If it’s sufficiently clean, it can be used for
groundwater recharge

29.  Nitrogen removal
 Ammonia (NH3) → nitrite (NO2
-
)→ nitrate (NO3
-
)
 Phosphorous removal
 Precipitation with iron or aluminums salt
 Lead to eutrophication
 May cause algae bloom

30.  Primary sludge usually have strong odors
 Secondary sludge have high concentration of
microorganism
 Goals of treatments are:
 Reduce odors
 Remove water reduce volume
 Decompose organic matter

31.  Untreated sludge are about 97 percent water
 Settling can reduce about 92 to 96 percent of
water
 dried sludge is called a sludge cake

32.  Aerobic digestion
 Anaerobic digestion
 composting

33.  Bacterial process
 Need oxygen
 Consume organic matter
 Convert into carbon dioxide (CO2)

34.  Bacterial process
 Do not require oxygen
 Consume organic matter
 Produce biogas, which can be used in
generators for electricity

35.  aerobic process
 requires the correct
mix of carbon,
nitrogen, oxygen and
water with sludge
 Generate large
amount of heat

36.  Superheat sludge and convert into small
granules that are rich in nitrogen
 Sell it to local farmer as fertilizer
 Spread sludge cake on the field
 Save landfill space

39. THANK
YOU......